The present invention relates to apparatus for cutting or shaping materials such as by heat-shaping, which operates by copying the outline of a pattern onto material which is to be worked on. This apparatus generally includes a member for following the pattern, the pattern follower-member being able to move in two mutually perpendicular directions and at least one heat-shaping tool which is likewise movable in two mutually perpendicular directions. A control device receives information from the follower member to correspondingly drive the follower-member to trace the pattern and to drive the tool to copy the pattern.
The expression "heat-shaping" as used herein is employed to denote the performing of a shaping, cutting etc. operation by the application of heat. As an example, heat-shaping apparatus may be a melting or oxidizing cutting machine which produces sequentially and automatically, cut articles of various shapes from sheets of steel, stainless steel, aluminium, light alloy, etc, from sheets of particle board, plywood, plastics materials, or from lengths of fabric.
The pattern to be copied may be formed by a design drawn on a sheet of ordinary paper or tracing paper, by a dark silhouette on a light background, by a flat steel template attached to a copying table, and the like.
The follower member may be a conventional device, such as an electronic follower with an optical tracker, particularly useful where a drawing or silhouette is traced out, or a magnetic follower or a curve tracer which are advantageous where a template is copied.
The aforementioned heat-shaping tool may be conventional, such as an oxy-acetylene gas cutting torch of the ordinary or flux-injection type, an electrical arc device employing a carbon electrode, a coated or tubular electrode, a consumable electrode (made of mild steel), or a refractory electrode (made of tungsten) which operates under a gaseous shielding atmosphere (the MIG or TIG processes), or a plasma torch, a laser, etc. A plurality of tools may be used in order to allow a plurality of worked parts to be produced simultaneously from a single pattern-following operation.
Presently known apparatus of this type for working on materials by thermal means is provided with a horizontal copying table on which the pattern is mounted, and the follower member is mounted on a framework arranged above the table, the framework and/or the follower member being movable in two mutually perpendicular directions which together define a horizontal plane, so that the entire pattern can be followed. The tool is mounted on an arm or the like which is secured to the framework and is arranged over another horizontal table which supports the material to be worked on. The tool thus performs the same movements as the follower member, that is, the tool is translated in the same directions as the follower member; This type of apparatus has the disadvantage that it requires a large amount of available space. The copying table occupies a large floor space whether the apparatus in use or not, and this occupied floor space, effectively is doubled when the apparatus is operating, owing to the fact that the cutting area in which the tool moves also is on the floor adjacent the table during such operation.